<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    let m = new Map()

    m.set('name','jack')//+1
    m.set('name1','jack1')//+1
    m.set('change',function () {
        ///
    })

    let key = {
        school:'guigu'
    };
    m.set(key,['beijing','shanghai','shenzhen'])

    m.size//daxiao

    m.delete('name')

    m.get('change')
    m.get(key)

    m.clear()

    for (let v of m ){
        console.log(v)
    }

</script>
</body>
</html>